package l.l.w.leetcode.Sum_3Closest;

import java.util.Arrays;

/**
 * LeetCode 13
 * Created by llw on 2017/10/26.
 * Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution.
 * For example, given array S = {-1 2 1 -4}, and target = 1.
 * The sum that is closest to the target is 2. (-1 + 2 + 1 = 2).
 *
 */
public class Sum_3Closest {
    public int threeSumClosest(int[] nums, int target) {
        Arrays.sort(nums);
        int n = nums.length;
        int result=nums[0]+nums[1]+nums[n-1];

        for(int i =0; i < n; ++i){
            int j = i+1, k = n-1;
            while (j < k){
                int sum = nums[i]+nums[j]+nums[k];
                if(sum == target) return sum;
                if(sum > target){
                    k--;
                }else{
                    j++;
                }
                if(Math.abs(sum - target) < Math.abs(result-target)){
                    result = sum;
                }
            }

        }
        return result;
    }
}
